Migrate from iOS 17 Observation to iOS 16-compatible Combine architecture.

Lower deployment target to iOS 16, replace @Observable with ObservableObject, add navigation and UI compatibility shims, and include login smoke UI tests.

Co-authored-by: Cursor <cursoragent@cursor.com>

suixinkan/Features/Auth/API/AuthAPI.swift

@@ -6,13 +6,12 @@
 //
 
 import Foundation
-import Observation
+import Combine
 
 @MainActor
-@Observable
 /// 登录认证 API，封装 v9 登录和账号选择相关接口。
 final class AuthAPI {
-    @ObservationIgnored private let client: APIClient
+    private let client: APIClient
 
     /// 初始化登录 API，并注入共享网络客户端。
     init(client: APIClient) {

suixinkan/Features/Auth/ViewModels/LoginViewModel.swift

@@ -6,7 +6,7 @@
 //
 
 import Foundation
-import Observation
+import Combine
 
 /// 登录输入焦点实体，标识当前需要聚焦的输入框。
 enum LoginField: Hashable {
@@ -68,17 +68,16 @@ enum LoginFlowError: LocalizedError {
 }
 
 @MainActor
-@Observable
 /// 登录页 ViewModel，负责表单状态、登录请求和多账号选择流程。
-final class LoginViewModel {
-    var username = "18651857230"
-    var password = "zhifly666"
-    var privacyChecked = false
-    var isLoading = false
-    var isSelectingAccount = false
-    var showsPassword = false
-    var showsAgreementSheet = false
-    var pendingAccountSelection: AccountSelectionPayload?
+final class LoginViewModel: ObservableObject {
+    @Published var username = "18651857230"
+    @Published var password = "zhifly666"
+    @Published var privacyChecked = false
+    @Published var isLoading = false
+    @Published var isSelectingAccount = false
+    @Published var showsPassword = false
+    @Published var showsAgreementSheet = false
+    @Published var pendingAccountSelection: AccountSelectionPayload?
 
     var canSubmit: Bool {
         isValidPhone && !trimmedPassword.isEmpty

suixinkan/Features/Auth/Views/AccountSelectionView.swift

@@ -44,7 +44,7 @@ struct AccountSelectionView: View {
     @ViewBuilder
     private var accountList: some View {
         if payload.accounts.isEmpty {
-            ContentUnavailableView(
+            AppContentUnavailableView(
                 "暂无可用账号",
                 systemImage: "person.crop.circle.badge.exclamationmark",
                 description: Text("当前账号没有可用的景区账号或门店账号，请联系管理员。")

suixinkan/Features/Auth/Views/LoginView.swift

@@ -9,17 +9,17 @@ import SwiftUI
 
 /// 登录页视图，负责展示登录表单、协议确认和多账号选择入口。
 struct LoginView: View {
-    @Environment(AppSession.self) private var appSession
-    @Environment(AccountContext.self) private var accountContext
-    @Environment(PermissionContext.self) private var permissionContext
-    @Environment(ToastCenter.self) private var toastCenter
-    @Environment(AuthAPI.self) private var authAPI
-    @Environment(ProfileAPI.self) private var profileAPI
-    @Environment(AccountContextAPI.self) private var accountContextAPI
-    @Environment(AuthSessionCoordinator.self) private var authSessionCoordinator
+    @EnvironmentObject private var appSession: AppSession
+    @EnvironmentObject private var accountContext: AccountContext
+    @EnvironmentObject private var permissionContext: PermissionContext
+    @EnvironmentObject private var toastCenter: ToastCenter
+    @Environment(\.authAPI) private var authAPI
+    @Environment(\.profileAPI) private var profileAPI
+    @Environment(\.accountContextAPI) private var accountContextAPI
+    @Environment(\.authSessionCoordinator) private var authSessionCoordinator
     @Environment(\.globalLoading) private var globalLoading
     @Environment(\.horizontalSizeClass) private var horizontalSizeClass
-    @State private var viewModel = LoginViewModel()
+    @StateObject private var viewModel = LoginViewModel()
     @FocusState private var focusedField: LoginField?
 
     private var contentMaxWidth: CGFloat {
@@ -76,11 +76,11 @@ struct LoginView: View {
                 )
             }
         }
-        .onChange(of: viewModel.username) { _, _ in
+        .onChange(of: viewModel.username) { _ in
             viewModel.normalizeUsernameCountryCodeIfNeeded()
             dismissLoginToastIfNeeded()
         }
-        .onChange(of: viewModel.password) { _, _ in
+        .onChange(of: viewModel.password) { _ in
             dismissLoginToastIfNeeded()
         }
         .task {
@@ -462,12 +462,12 @@ private struct LoginAgreementConsentSheet: View {
 
 #Preview {
     LoginView()
-        .environment(AppSession())
-        .environment(AccountContext())
-        .environment(PermissionContext())
-        .environment(ToastCenter())
-        .environment(AuthAPI(client: APIClient()))
-        .environment(ProfileAPI(client: APIClient()))
-        .environment(AccountContextAPI(client: APIClient()))
-        .environment(AuthSessionCoordinator())
+        .environmentObject(AppSession())
+        .environmentObject(AccountContext())
+        .environmentObject(PermissionContext())
+        .environmentObject(ToastCenter())
+        .environment(\.authAPI, AuthAPI(client: APIClient()))
+        .environment(\.profileAPI, ProfileAPI(client: APIClient()))
+        .environment(\.accountContextAPI, AccountContextAPI(client: APIClient()))
+        .environment(\.authSessionCoordinator, AuthSessionCoordinator())
 }